Electronic mail (or "e-mail") is becoming a popular way for people to communicate. Using e-mail, a person can send messages and other information (such as pictures, sound recordings, formatted documents, etc. that are in digital form) electronically to other e-mail users.
E-mail communication systems are generally regarded as multi-cast store-and-forward bi-directional communication systems. A user can send e-mail messages to one or more recipients at a time. An e-mail system is regarded as bi-directional as, usually, a user can both send and receive e-mail messages.
When using e-mail to communicate, a user will typically create a message using an e-mail program running on a computer that is or can be connected by a network to other computers. The message will include the e-mail address of the intended recipient. When the user has finished entering the message, the user will "send" the message to the intended recipient--the message is electronically transmitted via the computer network. The recipient, also using an e-mail program running on a computer connected to the computer network, can then read the received message.
A common computer network used to send and receive e-mail is the Internet. The Internet allows users to send and receive e-mail to and from computers around the world. Typically, each user will have an Internet e-mail address unique to that user, e.g., bob@pto.com. A user with an e-mail account and a computer that can connect to the Internet can easily send and receive e-mail over the Internet.
There are a number of ways that a user can connect to the Internet to send and receive e-mail. A user can have an account with a proprietary on-line network, such as, for example, Prodigy, America Online, CompuServe or Microsoft Network. Using a computer with a modem, the user dials up the on-line network's access number and connects to the on-line network. The user can then send and receive e-mail to and from other users of the on-line network and, provided that the on-line network is connected to the Internet, with those having an Internet e-mail address. An alternative method to connect with the Internet is via an Internet Service Provider. Using a modem, the user dials the access number of the Internet Service Provider, and establishes a connection with a computer "directly" connected to or part of the Internet. The user can then operate an e-mail program, such as Eudora, to send and receive e-mail over the Internet.
In many existing systems, users read and write e-mail while on-line, i.e., while connected to the on-line network or the Internet Service Provider. Costs of operating the on-line network (including communication and hardware costs) are higher when users are connected to the network. Also, some on-line networks and Internet Access Providers charge per minute of connect time. Accordingly, it is more cost effective if users read and write e-mail messages when off-line (e.g., when not connected to the on-line network).
Some existing on-line services display advertising to users. For example, advertisements are shown on part of the screen to users of the America Online network. When accessing certain World Wide Web sites on the Internet, advertisements are often included as part of the web page seen by the user. Often in such systems, each user accessing a certain screen or site is shown the same advertisement. Sophisticated systems have the capability to change the advertisement after a certain period of time. However, in such systems the user must remain connected to the network to see the replacement advertisement.
When using a browser program (such as Netscape's Navigator program) to access pages on the World Wide Web, information, which may include advertisements, may be downloaded and cached at a user's computer. This information can be flushed from the cache at a later time, as determined by the browser program. In some cases, this information may be flushed when the browser program is "off-line." However, advertisements are not automatically replaced in a web page and new, unseen advertisements are not displayed as part of a web page when in such disconnected mode.
Accordingly, there is a need for a system that displays and automatically replaces displayed advertisements while disconnected from the network.
In particular, there is a need for an e-mail system that operates mostly off-line and that can display and automatically replace displayed advertisements while off-line.
Advertisers find it desirable to target advertisements to relevant potential customers. For example, an advertiser of stockings would prefer to target women rather than men with its advertising. A Boston restaurant would prefer to target residents of Boston and business travelers rather than children living in San Francisco. Moreover, advertisers prefer to pay for advertising based upon the number of relevant consumers who are actually exposed to the advertisement. For prior on-line systems and networks, including the World Wide Web, it is often difficult for an advertiser to precisely determine whether its advertisements were actually viewed by a user and for how long, and whether the advertisement induced a response. Accordingly, there exists a need for a targeted advertisement system that also can provide information as to the characteristics of those who were exposed to each advertisement, for how long the user was exposed, and at what times.
Existing e-mail systems have other disadvantages. In existing dial-up e-mail systems, a user is provided with an access telephone number to connect to the network. Typically, at the network there are a number of mail servers and each user's received e-mail messages are stored on one of those mail servers. Because many users use the same access number to connect to the network, the network requires capabilities to switch users to the mail server that stores that user's e-mail. Existing e-mail networks determine at the server side and while the user is on-line who the user is and that user's mail server, and then switch the user to that mail server--a time consuming operation, especially if there are many users accessing the network. There exists a need for an e-mail system where the network does not have to decide, as part of the switching process, which mail server is to be accessed by each user.